THE SHORE FISHES OF PERU 321 



with a more or less straight to round margin; anal with 3 or 4 strong 

 spines, the soft part similar to that of dorsal, though generally with 

 somewhat fewer rays. 



A single species, new to the fauna of Peru, is included in the collec- 

 tions studied. 



CHAETODON HUMERALIS Gunther 



Chaetodon humeralis GtJNTHER, 1860, p. 19, "Sandwich Islands," regarded as an 

 error; Panama Bay has been suggested as the correct locality (original de- 

 scription). — Meek and Hildebrand, 1928, p. 770, Panama Bay (synonymy; 

 description; range). 



Head 2.65 to 2.75; depth 1.3 to 1.35; D. XIII, 20; A. Ill, 16 or 17; 

 P. 16; scales along middle of side 33 to 35. 



Body very strongly compressed, its greatest thickness about a 

 fou^-th of its depth; back much elevated; dorsal profile concave over 

 the head; caudal peduncle short, very strongly compressed, 2.7 to 3.0 

 in head; snout rather pointed, 3.1 to 3.2 in head; eye 2.7 to 3.2; 

 interorbital somewhat expanded, 3.5 to 3.9; mouth very small, termi- 

 nal; maxillary reaching nearly to vertical from anterior nostril, 4.15 

 to 4.4 in head; teeth very fine, in a broad band in each jaw, arranged 

 more or less in series ; lateral line strongly arched, ending under poste- 

 rior rays of dorsal; scales ctenoid, much reduced on head, covering most 

 of soft parts of dorsal and anal, also extending more or less on bases 

 of caudal, ventral, and pectoral, the rows running obliquely upward 

 and backward on side, becoming nearly horizontal on lower parts, 

 seven full rows between lateral line and base of first dorsal spine; 

 dorsal fin continuous, not definitely indented, the third and fourth 

 spines longest, 1.3 in head; soft part of dorsal with round margin, 

 longest rays higher than posterior spines, but shorter than the longest 

 spines; caudal with nearly straight margin; anal with strong spines, 

 the second longer and stronger than the third, 1.8 to 1.95 in head, 

 soft part similar to that of dorsal and coterminal with it; ventral large, 

 reaching origin of anal, its spine strong, 1.5 to 1.75 in head; pectoral 

 moderately long, 1.1 to 1.25 in head, 3.0 to 3.3 in length. 



General color light silvery brown; rows of scales marked with dark 

 lines; tip of snout black; a dark band, narrower than eye, extending 

 from nape across eye to lower margin of opercle; a broader dark 

 band extending from first three dorsal spines across and somewhat 

 below base of pectoral; a still broader dark band reaching from the 

 last few dorsal spines and first soft rays of dorsal to anal spines; a 

 narrow dark band at base of caudal, and a very narrow one on caudal 

 fin; a dark intramarginal band on soft dorsal and anal, these fins, as 

 well as the caudal and pectoral, otherwise plain translucent; ventral 

 largely dusky. 



The description is based on three specimens, respectively 42, 43, and 

 60 mm. (33, 33, and 49 mm. to base of caudal) long. These specimens, 



